Fix UnSatisfiedLinkError when trying to load non-existent libraries

.github/workflows/build-test.yml

@@ -104,5 +104,9 @@ jobs:
           - name: Run TestCpuFeatures
             run: ./gradlew :snaploader-examples:TestCpuFeatures :snaploader-examples:run
 
+          - name: Run TestBrokenFeatures
+            run: ./gradlew :snaploader-examples:ReflectiveLauncher :snaploader-examples:run --args="electrostatic4j.snaploader.examples.TestBrokenFeatures"
+
           - name: List extracted files
             run: ls ./snaploader-examples/libs/
+

snaploader-examples/src/main/java/electrostatic4j/snaploader/examples/TestBrokenFeatures.java

@@ -0,0 +1,154 @@
+/*
+ * Copyright (c) 2023-2026, The Electrostatic-Sandbox Distributed Simulation Framework, jSnapLoader
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * * Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ *
+ * * Neither the name of 'AvrSandbox' nor the names of its contributors
+ *   may be used to endorse or promote products derived from this software
+ *   without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package electrostatic4j.snaploader.examples;
+
+import electrostatic4j.snaploader.LibraryInfo;
+import electrostatic4j.snaploader.NativeBinaryLoader;
+import electrostatic4j.snaploader.NativeBinaryLoadingListener;
+import electrostatic4j.snaploader.filesystem.DirectoryPath;
+import electrostatic4j.snaploader.filesystem.FileExtractionListener;
+import electrostatic4j.snaploader.filesystem.FileExtractor;
+import electrostatic4j.snaploader.filesystem.FileLocator;
+import electrostatic4j.snaploader.platform.util.DefaultDynamicLibraries;
+import electrostatic4j.snaploader.platform.NativeDynamicLibrary;
+import electrostatic4j.snaploader.platform.util.NativeVariant;
+import electrostatic4j.snaploader.platform.util.PlatformPredicate;
+import electrostatic4j.snaploader.platform.util.DefaultPropertiesProvider;
+import electrostatic4j.snaploader.LoadingCriterion;
+import electrostatic4j.snaploader.util.CallingStackMetaData;
+
+/**
+ * Tests basic features of the {@link NativeBinaryLoader} API.
+ *
+ * @author pavl_g
+ */
+public final class TestBrokenFeatures {
+
+    protected static final LibraryInfo libraryInfo = new LibraryInfo(getJarFilePath(),
+            new DirectoryPath(DefaultDynamicLibraries.LINUX_X86.getPlatformDirectory()),
+            getLibraryBaseName(),
+            getLibrariesAbsolutePath());
+
+    protected static NativeBinaryLoader loader;
+
+    public static final NativeDynamicLibrary[] libraries = new NativeDynamicLibrary[] {
+            DefaultDynamicLibraries.LINUX_X86,
+            new NativeDynamicLibrary("nonexistent/directory", "junk", PlatformPredicate.LINUX_X86_64),
+            new NativeDynamicLibrary("lib/windows/x86", "libjmealloc.dll", PlatformPredicate.WIN_X86),
+            new NativeDynamicLibrary("lib/windows/x86-64", "libjmealloc.dll", PlatformPredicate.WIN_X86_64),
+            DefaultDynamicLibraries.MAC_X86,
+            DefaultDynamicLibraries.MAC_X86_64,
+    };
+
+    public static void main(String[] args) throws Exception {
+        if (loader == null) {
+            loader = new NativeBinaryLoader(libraryInfo);
+        }
+        loader.registerNativeLibraries(libraries).initPlatformLibrary();
+        loader.setLoggingEnabled(false);
+        loader.setRetryWithCleanExtraction(true);
+        /* Native dynamic library properties */
+        printDetails(loader);
+        loader.setNativeBinaryLoadingListener(new NativeBinaryLoadingListener() {
+            @Override
+            public void onLoadingSuccess(NativeBinaryLoader nativeBinaryLoader, CallingStackMetaData callingStackMetaData) {
+
+            }
+
+            @Override
+            public void onLoadingFailure(NativeBinaryLoader nativeBinaryLoader, CallingStackMetaData callingStackMetaData) {
+                System.err.println(callingStackMetaData.getErrorCause());
+            }
+
+            @Override
+            public void onRetryCriterionExecution(NativeBinaryLoader nativeBinaryLoader, CallingStackMetaData callingStackMetaData) {
+
+            }
+        });
+
+        loader.setLibraryExtractionListener(new FileExtractionListener() {
+            @Override
+            public void onExtractionCompleted(FileExtractor fileExtractor) {
+                System.out.println("Extracted Successfully!");
+            }
+
+            @Override
+            public void onExtractionFailure(FileExtractor fileExtractor, Throwable throwable) {
+                System.err.println(throwable.toString());
+            }
+
+            @Override
+            public void onExtractionFinalization(FileExtractor fileExtractor, FileLocator fileLocator) {
+                System.out.println("Finalization State has been reached!");
+            }
+        });
+
+        loader.loadLibrary(LoadingCriterion.INCREMENTAL_LOADING);
+    }
+
+    protected static void printDetails(NativeBinaryLoader loader) {
+        System.out.println("--------------------------------------------------------------");
+        System.out.println("OS: " + NativeVariant.OS_NAME.getProperty());
+        System.out.println("ARCH: " + NativeVariant.OS_ARCH.getProperty());
+        System.out.println("VM: " + NativeVariant.JVM.getProperty());
+        System.out.println("--------------------------------------------------------------");
+        System.out.println("Jar Path: " + loader.getNativeDynamicLibrary().getJarPath());
+        System.out.println("Library Directory: " + loader.getNativeDynamicLibrary().getPlatformDirectory());
+        System.out.println("Compressed library path: " + loader.getNativeDynamicLibrary().getCompressedLibrary());
+        System.out.println("Extracted library absolute path: " + loader.getNativeDynamicLibrary().getExtractedLibrary());
+        System.out.println("Is Extracted: " + loader.getNativeDynamicLibrary().isExtracted());
+        System.out.println("--------------------------------------------------------------");
+    }
+
+    protected static DirectoryPath getLibrariesAbsolutePath() {
+        return new DirectoryPath(DefaultPropertiesProvider.USER_DIR.getSystemProperty(), "libs");
+    }
+
+    protected static DirectoryPath getJarFilePath() {
+        return new DirectoryPath(getLibrariesAbsolutePath().getPath(), getJarFile());
+    }
+
+    protected static String getNativeDynamicLibraryPath() {
+        return getLibrariesAbsolutePath().getPath() +
+                DefaultPropertiesProvider.FILE_SEPARATOR.getSystemProperty() +
+                "lib" + getLibraryBaseName() + ".so";
+    }
+
+    protected static String getJarFile() {
+        return "jme3-alloc-desktop-1.0.0-pre-gamma-2.jar";
+    }
+
+    protected static String getLibraryBaseName() {
+        return "jmealloc";
+    }
+}

snaploader/src/main/java/electrostatic4j/snaploader/NativeBinaryLoader.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2023-2025, The Electrostatic-Sandbox Distributed Simulation Framework, jSnapLoader
+ * Copyright (c) 2023-2026, The Electrostatic-Sandbox Distributed Simulation Framework, jSnapLoader
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -33,6 +33,7 @@
 package electrostatic4j.snaploader;
 
 import java.io.File;
+import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.nio.file.FileSystems;
 import java.util.Arrays;
@@ -49,6 +50,7 @@
 import electrostatic4j.snaploader.platform.util.NativeVariant;
 import electrostatic4j.snaploader.platform.util.PropertiesControllerNamespace;
 import electrostatic4j.snaploader.platform.util.PropertiesController;
+import electrostatic4j.snaploader.throwable.LibraryNotFoundException;
 import electrostatic4j.snaploader.throwable.LoadingRetryExhaustionException;
 import electrostatic4j.snaploader.throwable.UnSupportedSystemError;
 import electrostatic4j.snaploader.util.CallingStackMetaData;
@@ -183,12 +185,13 @@ public NativeBinaryLoader loadLibrary(LoadingCriterion criterion) throws Excepti
             throw new IllegalArgumentException("Native library data structures cannot be null!");
         }
         // commands and loads the library from the system directories
-        if (NativeVariant.Os.isAndroid() || criterion == LoadingCriterion.SYSTEM_LOAD) {
+        if (NativeVariant.Os.isAndroid() ||
+                criterion == LoadingCriterion.SYSTEM_LOAD) {
             loadSystemBinary(nativeDynamicLibrary);
             loadingCriterion = LoadingCriterion.SYSTEM_LOAD;
             return this;
         }
-        if (criterion == LoadingCriterion.INCREMENTAL_LOADING && nativeDynamicLibrary.isExtracted()) {
+        if (criterion == LoadingCriterion.INCREMENTAL_LOADING) {
             loadBinary(nativeDynamicLibrary, criterion);
             loadingCriterion = LoadingCriterion.INCREMENTAL_LOADING;
             return this;
@@ -336,14 +339,17 @@ protected void loadSystemBinary(NativeDynamicLibrary dynamicLibrary) {
      */
     protected void loadBinary(NativeDynamicLibrary library, LoadingCriterion loadingCriterion) throws Exception {
         try {
+            if (!nativeDynamicLibrary.exists()) {
+                throw new LibraryNotFoundException("Library " + nativeDynamicLibrary.getExtractedLibrary() + " not found!");
+            }
             System.load(library.getExtractedLibrary());
             SnapLoaderLogger.log(Level.INFO, getClass().getName(), "loadBinary", "Successfully loaded library: "
                     + library.getExtractedLibrary());
             if (nativeBinaryLoadingListener != null) {
                 nativeBinaryLoadingListener.onLoadingSuccess(this,
                         new CallingStackMetaData(Thread.currentThread().getStackTrace()[1], loadingCriterion));
             }
-        } catch (final UnsatisfiedLinkError error) {
+        } catch (final UnsatisfiedLinkError | FileNotFoundException error) {
             SnapLoaderLogger.log(Level.SEVERE, getClass().getName(), "loadBinary", "Cannot load the dynamic library: "
                     + library.getExtractedLibrary(), error);
             if (nativeBinaryLoadingListener != null) {

snaploader/src/main/java/electrostatic4j/snaploader/filesystem/FileExtractor.java

@@ -66,6 +66,8 @@ public class FileExtractor implements OutputStreamProvider {
      */
     protected String destination;
 
+    protected File extractableFile;
+
     private static final int EOF = -1; /* End-of-filesystem */
 
     /**
@@ -103,6 +105,7 @@ public void initialize(int size) throws Exception {
                 return;
             }
             this.fileOutputStream = new FileOutputStream(destination);
+            extractableFile = new File(destination);
             SnapLoaderLogger.log(Level.INFO, getClass().getName(), "initialize(int)",
                     "File extractor initialized with hash key #" + getHashKey());
         } catch (Exception e) {
@@ -149,6 +152,14 @@ public void extract() throws IOException, FileNotFoundException {
                 fileExtractionListener.onExtractionCompleted(this);
             }
         } catch (Exception e) {
+            // ensure deleting the blank created files
+            // by the Java Legacy FileOutputStream upon failure!
+
+            // blank created files; create an opaque behavior
+            // that triggers an UnSatisfiedLinkError: file is too short
+            // as a result of trying to load corrupted files
+            // on the next runtime...
+            delete();
             if (fileExtractionListener != null) {
                 fileExtractionListener.onExtractionFailure(this, e);
             }
@@ -160,6 +171,20 @@ public void extract() throws IOException, FileNotFoundException {
         }
     }
 
+    /**
+     * Deletes the associated file created by the Legacy
+     * Java OutputStream {@link FileExtractor#getFileOutputStream()}.
+     *
+     * @return true if the file has been deleted, false otherwise if the
+     * file is not defined or doesn't exist.
+     */
+    protected boolean delete() {
+        if (extractableFile == null || !extractableFile.exists()) {
+            return false;
+        }
+        return extractableFile.delete();
+    }
+
     @Override
     public void close() throws Exception {
         if (fileOutputStream != null) {

snaploader/src/main/java/electrostatic4j/snaploader/platform/NativeDynamicLibrary.java

@@ -146,6 +146,13 @@ public void initWithLibraryInfo(LibraryInfo libraryInfo) {
         }
     }
 
+    public boolean exists() {
+        if (jarPath == null || libraryFile == null || directoryPath == null) {
+            return false;
+        }
+        return new File(getExtractedLibrary()).exists();
+    }
+
     /**
      * Retrieves the absolute path for the jar compression as specified by the {@link LibraryInfo} API.
      * 

snaploader/src/main/java/electrostatic4j/snaploader/throwable/LibraryNotFoundException.java

@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2023-2026, The Electrostatic-Sandbox Distributed Simulation Framework, jSnapLoader
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * * Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ *
+ * * Neither the name of 'Electrostatic-Sandbox' nor the names of its contributors
+ *   may be used to endorse or promote products derived from this software
+ *   without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package electrostatic4j.snaploader.throwable;
+
+import java.io.FileNotFoundException;
+
+/**
+ * A business exception that is thrown to indicate that a library, that is
+ * tried to be loaded, doesn't exist.
+ *
+ * @author pavl_g
+ */
+public class LibraryNotFoundException extends FileNotFoundException {
+    public LibraryNotFoundException(String message) {
+        super(message);
+    }
+}